KR101396002B1 - Polycrystalline cobalt-nickel-manganese ternary positive material, preparation method thereof and lithium ion secondary battery - Google Patents

Abstract

A polycrystalline cobalt-nickel-manganese three-electrode cathode material is provided. The polycrystalline cobalt-nickel-manganese three-electrode cathode material may include Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1 - (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _{1 -x} O ₂ , Li _z Co _x Ni _{1 - x} O _2, and Li ₂ MnO ₃ . A method for producing a cathode material by high temperature fusion is provided. The anode material has a compression density of 3.9 to 4.3 g / cm ³ , a capacity of 145 mAh / g or more when the discharge magnification is 0.5 to 1 C, and a capacity retention rate of more than 90% after 300 cycles. The cathode material produced by high temperature fusion has high volume energy density, excellent electrochemical performance and improved safety, and the material cost is low. Further, a lithium ion secondary battery including a cathode material is provided.

Description

TECHNICAL FIELD [0001] The present invention relates to a polycrystalline cobalt-nickel-manganese three-electrode cathode material, a method for producing the same, and a lithium ion secondary battery,

The present invention relates to a cathode material for a lithium ion battery, a method for producing the same, and a lithium ion battery made from the cathode material. More particularly, the present invention relates to a polycrystalline cobalt-nickel-manganese (Co-Ni-Mn) To a lithium ion secondary battery manufactured using a polycrystalline Co-Ni-Mn three-dimensional material.

Since the lithium ion battery was commercialized in 1991, the demand for the application has increased, and the energy density of the lithium ion battery has been increasing according to the market demand. Specifically, the energy density of a lithium ion battery is divided into a volume energy density and a weight energy density. What is required in the market is to simultaneously increase the volume energy density and the weight energy density. To increase the volumetric energy density of the battery under the same capacity, the unit volume of the battery active material should be increased. Lithium cobalt oxide is currently being used in large quantities as lithium cobalt oxide. It is the first matured material that has been commercialized and widely used in small-sized, low-power portable electronic products such as mobile phones, notebook computers, and digital electronic products . However, due to limited resources and higher safety requirements, finding cathode materials with low cost, low energy density, high safety, and low cobalt or cobalt content has become the direction of development of lithium cathode materials. After constant development, the Co-Ni-Mn system and its Mn system exceed the lithium cobalt oxide already in capacity and the safety is better than the lithium cobalt oxide and the cost is relatively low. However, according to the evaluation of the three-way material, the three-way material is still lower in volume energy density than lithium cobalt oxide because of low discharge potential and low compression density of pole pieces, Mn system is difficult to meet the market demand for high performance cathode materials. The Co-Ni-Mn type ternary material and its Mn system can not yet replace the application demand of lithium cobalt oxide in advanced lithium ion secondary batteries. Conventional manufacturing methods generally involve mixing two kinds of materials together by a mechanical mixing method, and achieve the purpose of lowering the cost and improving the safety through a method of mixing the materials. For example, in Sony Japan, attempts have been made to improve overcharge safety and thermal stability by mixing LiCoO ₂ and LiMn ₂ O _4. This simple physical mixing method often affects material performance, such as poor compression density, It is only a simple arithmetic mean of the mixed materials.

An object of the present invention is to provide a polycrystalline Co-Ni-Mn three-way material, a method for producing the same, and a lithium ion secondary battery, and to solve the volume energy density, safety and discharge potential of the cathode material, It is a technical task.

The present invention uses the following technique: Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O _2, Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , Li ₂ MnO ₃ (where x, y, x + y <1, z? 1), and has a polycrystalline layer structure, element Li: Co: Ni: Mn molar ratio is 1 to 1.2: 0.4 to 0.7: 0.2 to 0.5: 0.1 to 0.3, and a particle size of 8-20 microns, and the compressed density of 3.9 ~ 4.3g / cm ^3, the discharge ratio Wherein the capacity is 145 mAh / g or more at a temperature of 0.5 to 1C, and the cyclic capacity retention rate of 300 times or more is 90% or more.

The method for producing polycrystalline Co-Ni-Mn three-cathode material includes the following steps:

1. Preparation of Precursor: 6 to 25 g of polyethylene glycol was placed in 300 to 500 ml of LiAc, LiOH or LiNO ₃ solution having a lithium element concentration of 1.0 to 1.2 mol / L, and at least one kind of salt compound of Co, Ni and Mn elements And the mixture was stirred for 120 minutes under the conditions of 20 to 60 캜 and a rotation speed of 20 to 120 rpm so that the total content of Co, Ni and Mn elements was 0.3 to 1.0 mol. Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , and Li _z Co _{1- (x + y)} were obtained by drying and dehydrating the mixture at a temperature of 150 to 250 ° C. for 2 to 10 hours and dispersing the mixture in a ball mill at a rotation speed of 200 to 1000 rpm for 30 minutes. _{) X} Ni _y Mn ₂ O ₃ , Li _z Ni _x Mn _{1 - x} O _{2 ,} Li _z Co _x Ni _{1 - x} O ₂ or Li ₂ MnO ₃ wherein x, y, x + y <Lt; / RTI &gt; oxide precursor;

2. Preparation of Polycrystalline Co-Ni-Mn Ternary Cathode Materials The precursory composite sintering method is used for the preparation of the polycrystalline Co-Ni-Mn ternary anode materials: Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O _{2 , Li z Ni x Mn 1-} x O 2, Li z Co x Ni 1-x O 2, Li 2 MnO 3 for the oxide precursor two or more of Li: Co: Ni: Mn molar ratio is 1 to 1.2: 0.4 and 0.7: 0.2-0.5: 0.1-0.3, the mixture is homogeneously mixed for 60 minutes with a ball mill at a rotational speed of 200 to 1000 rpm. Thereafter, the mixture is directly poured into a box-type furnace, sintered at a temperature of 750 to 950 ° C for 5 to 15 hours, naturally cooled to lower the temperature to room temperature, air flow pulverization is carried out, -Mn three-anode material;

Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ were directly put into a box furnace and sintered at a temperature of 600 to 850 ° C for 5 to 15 hours for initial sintering. The molar ratio of Li: Co: Ni: Mn = 1 ~ 1.2: 0.4 to 0.7: 0.2 - 0.5: according to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- (x + y) Ni x Mn y O 2, Li z The initial sintered product of two or more precursors in Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ was homogeneously mixed with a ball mill at a rotation speed of 500 rpm for 60 minutes, And sintered under the temperature of 750 ~ 980 ℃ for 4 ~ 10 hours. The mixture was cooled to room temperature and the air flow was pulverized. The pressure of 0.4 ~ 1.0MPa was applied to the polycrystalline Co-Ni-Mn tri- Get;

Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Each of the precursors of Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ is put directly into a box-type furnace, sintered at a temperature of 850 to 980 ° C for 5 to 10 hours, air flow pulverization is carried out, , And classified by a sample sheave to have a particle size D50 of 8 to 20 microns. After that Li: Co: Ni: Mn molar ratio of 1 ~ 1.2: 0.4 to 0.7: 0.2 - 0.5: According to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- _{(x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , and Li ₂ MnO ₃ are homogeneously mixed, , Sintered at a temperature of 350 to 850 캜 for 0.5 to 5 hours, air-flow pulverized, and an air pressure of 0.4 to 1.0 MPa to obtain a polycrystalline Co-Ni-Mn triode cathode material.

In the process of the present invention, the Co, Ni, Mn salt compounds are hydroxyl compounds, oxalates or carbonates.

In the method of the present invention, after air flow milling, it is classified into a sample sheave to control the particle size to D50 = 8 to 20 microns.

A method of making a polycrystalline Co-Ni-Mn three-cathode material comprises the following steps:

1. Preparation of Precursor: An aqueous nitrate solution having a mass concentration of 16% was prepared from nitrate having a total content of at least one of Co, Ni, and Mn of 0.5 to 1.0 mol, and the mixture was heated at 30 to 80 캜 and at a rotation speed of 20 to 120 rpm A lithium nitrate aqueous solution having a lithium element content of 1.0 to 1.2 mol and a mass concentration of 10 to 25% is gradually added dropwise and reacted for 60 to 120 minutes. Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li ₂ MnO ₂ , and Li _z MnO ₂ were obtained by directly dipping the mixture in a box type furnace at a temperature of 150 to 250 ° C. for 2 to 10 hours and dispersing the mixture in a ball mill at a rotation speed of 200 to 1000 rpm for 30 minutes. ₂ , Li _z Co _{1 - (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _{1 -x} O ₂ , Li _z Co _x Ni _{1 - x} O ₂ or Li ₂ MnO ₃ , x + y &lt; 1, z &gt; = 1);

2. Preparation of Polycrystalline Co-Ni-Mn Ternary Cathode Materials The precursory composite sintering method is used for the preparation of the polycrystalline Co-Ni-Mn ternary anode materials: Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O _{2 , Li z Ni x Mn 1-} x O 2, Li z Co x Ni 1-x O 2, Li 2 MnO 3 for the oxide precursor two or more of Li: Co: Ni: Mn molar ratio is 1 to 1.2: 0.4 and 0.7: 0.2-0.5: 0.1-0.3, the mixture is homogeneously mixed for 60 minutes with a ball mill at a rotational speed of 200 to 1000 rpm. Then, the mixture was directly put into a box type furnace, sintered at 750 to 950 ° C for 5 to 15 hours, naturally cooled to lower the temperature to room temperature, and pulverized by air flow. The pressure of the polycrystalline Co-Ni- Mn trivalent anode material;

Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ were directly put into a box furnace and sintered at a temperature of 600 to 850 ° C for 5 to 15 hours for initial sintering. The molar ratio of Li: Co: Ni: Mn = 1 ~ 1.2: 0.4 to 0.7: 0.2 - 0.5: according to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- (x + y) Ni x Mn y O 2, Li z Two or more precursors of Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , and Li ₂ MnO ₃ were homogeneously mixed with a ball mill at a rotation speed of 500 rpm for 60 minutes, And sintered under the temperature of 750 ~ 980 ℃ for 4 ~ 10 hours. The mixture was cooled to room temperature and the air flow was pulverized. The pressure of 0.4 ~ 1.0MPa was applied to the polycrystalline Co-Ni-Mn tri- Get;

Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Each of the precursors of Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ was put directly into a box-type furnace, sintered at a temperature of 850 to 980 ° C for 5 to 10 hours, air-flow pulverized, Classified with a sample sheave to have a particle size D50 of 8 to 20 microns. After that Li: Co: Ni: Mn molar ratio of 1 ~ 1.2: 0.4 to 0.7: 0.2 - 0.5: According to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- _{(x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , and Li ₂ MnO ₃ are homogeneously mixed, And sintered at a temperature of 350 to 850 캜 for 0.5 to 5 hours and air-jet milled to obtain a polycrystalline Co-Ni-Mn three-way cathode material at an air pressure of 0.4 to 1.0 MPa.

In the method of the present invention, after air flow pulverization, the sample sieve is classified to control the particle size to D50 = 8 to 20 microns.

1. A lithium ion secondary battery comprising a positive electrode material, wherein the positive electrode material comprises Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _at least two base crystal structures of _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , Li ₂ MnO ₃ (where x, y, x + y <1, And has a polycrystalline layer structure and a molar ratio of element Li: Co: Ni: Mn of 1 to 1.2: 0.4 to 0.7: 0.2 to 0.5: 0.1 to 0.3, a particle size of 8 to 20 microns and a compression density of 3.9 to 4.3 g / cm &lt; ³ &gt;, a capacity of 145 mAh / g or more when the discharge magnification is 0.5 to 1C, and a cyclic capacity retention rate of 300 times or more of 90% or more.

Compared with the prior art, the present invention provides polycrystalline Co-Ni-Mn ternary cathode materials by producing precursors through high-temperature fusing, and by growing the different cathode materials into one overall structure, The anode material is manufactured, and the material produced has excellent electrochemical performance and a higher volume energy density, is safe, and has a low cost of materials.

1 is an X-ray diffraction spectrum of Reference Example 7. Fig.
2 is an X-ray diffraction spectrum of Example 8. Fig.
3 is an X-ray diffraction spectrum of Example 9. Fig.
4 is an X-ray diffraction spectrum of Reference Example 10. Fig.
5 is an X-ray diffraction spectrum of Example 11. Fig.
6 is an X-ray diffraction spectrum of Example 12. Fig.
7 is an X-ray diffraction spectrum of Example 13. Fig.
8 is an X-ray diffraction spectrum of Reference Example 14. Fig.
9 is an X-ray diffraction spectrum of Example 15. Fig.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings and embodiments. Poly-Co-Ni-Mn three won positive electrode material of the present invention is _{Li z CoO 2, Li z NiO} 2, Li z MnO 2, Li z Co 1- (x + y) Ni x Mn y O 2, Li z Ni x Mn 1 - _{x O 2, Li z Co x} Ni 1 - x O 2, Li 2 MnO 3 ( wherein x, y, x + y <1, a z≥1) having a base crystal structure of two or more of the layered crystal is , A particle size of 8 to 20 microns, a compression density of 3.9 to 4.3 g / cm ³ , a discharge capacity of 0.5 to 1 C, a circulation capacity retention rate of 300 times or more is 90% or more, a processing performance is good, Do not.

A method for producing a polycrystalline Co-Ni-Mn three-way cathode material of the present invention comprises the steps of:

1. Preparation of precursor:

Method 1: 6 to 25 g of polyethylene glycol is placed in 300 to 500 ml of LiAc, LiOH or LiNO ₃ solution having a lithium element concentration of 1.0 to 1.2 mol / L, and one or more of the salts of Co, Ni and Mn elements are added dropwise Mix. Thereafter, the mixture was stirred for 120 minutes under the conditions of 20 to 60 ° C and a rotation speed of 20 to 120 rpm to give 0.3 to 1.0 mol of Co, Ni, and Mn elements. The mixture was directly introduced into a box- by dehydration of 2-10 hours drying at a temperature, and dispersed for 30 minutes by a ball mill in the rotational speed _{200 ~ 1000rpm Li z CoO 2,} Li z NiO 2, Li z MnO 2, Li z Co 1- (x + y) Ni x Mn y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O _2, or an oxide precursor of Li ₂ MnO ₃ (where x, y, x + y <1, z? . The Co, Ni, Mn salt compounds are hydroxyl compounds, oxalates or carbonates.

Method 2: An aqueous nitrate solution having a mass concentration of 16% was prepared from nitrate having a total content of Co, Ni, Mn of 0.5 to 1.0 mol, and the lithium element content was measured at 30 to 80 캜 and at a rotation speed of 20 to 120 rpm Of lithium nitrate aqueous solution having a mass concentration of 10 to 25% is gradually added dropwise and the mixture is reacted for 60 to 120 minutes. Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li ₂ MnO ₂ , and Li _z MnO ₂ were obtained by directly dipping the mixture in a box type furnace at a temperature of 150 to 250 ° C. for 2 to 10 hours and dispersing the mixture in a ball mill at a rotation speed of 200 to 1000 rpm for 30 minutes. ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ or Li ₂ MnO ₃ , x + y &lt; 1, z? 1).

2. Preparation of Polycrystalline Co-Ni-Mn Ternary Cathode Material:

Method 1: Precursor composite sintering method: Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Two or more kinds of oxide precursors of Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ with a molar ratio of Li: Co: Ni: Mn = 1 to 1.2: 0.4 to 0.7: 0.2 to 0.5: 0.1 to 0.3, The mixture is homogeneously mixed with a ball mill at 200 to 1000 rpm for 60 minutes. Thereafter, the mixture is directly introduced into a box-type furnace, sintered at a temperature of 750 to 950 ° C for 5 to 15 hours, naturally cooled to lower the temperature to room temperature, air flow pulverization is carried out, the air pressure is set to 0.4 to 1.0 MPa, And the particle size is controlled to D50 = 8 to 20 microns to obtain a polycrystalline Co-Ni-Mn triode cathode material.

Method 2: Intermediate composite sintering: Li _z CoO _2, Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ were directly placed in a box-type furnace and sintered at a temperature of 600 to 850 ° C for 5 to 15 hours to prepare a precursor. Li / Co: Ni: Mn molar ratio = 1 Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni ₂ O ₃ , _The initial sintered product of two or more precursors in _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , and Li ₂ MnO ₃ was homogeneously mixed with a ball mill at a rotation speed of 500 rpm for 60 minutes, And sintered under a temperature of 750 to 980 캜 for 4 to 10 hours, air cooling was carried out by lowering the temperature to room temperature and the air flow was pulverized. The air pressure was adjusted to 0.4 to 1.0 MPa and classified by a sample sheave to obtain a particle size D50 = 8 To 20 microns to obtain a polycrystalline Co-Ni-Mn three-electrode material.

Method 3: final product composite sintering method: Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ were directly put into a box-type furnace, sintered at a temperature of 850 to 980 ° C for 5 to 10 hours, air flow pulverization was carried out, And classified with a sample sheave to have a particle size of D50 = 8 to 20 microns. After that Li: Co: Ni: Mn molar ratio of 1 ~ 1.2: 0.4 to 0.7: 0.2 - 0.5: According to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- _{(x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , and Li ₂ MnO ₃ are uniformly mixed, And sintered under the temperature of 350 to 850 ° C for 0.5 to 5 hours and air flow pulverization was carried out. The pressure was adjusted to 0.4 to 1.0 MPa and classified with a sample sheave to control the particle size to D50 = 8 to 20 microns to obtain polycrystalline Co-Ni- Mn trivalent anode material is obtained.

Dewatering and drying equipment used in the present invention: KSF1100-V type box furnace of Eising Co., Ltd. is used. Crushing facility: SHQM-type twin ball mill of Lyeong River Experiment technician is used. Air flow milling: Use an MX-50 air flow mill of the crushing equipment construction work. Classification facility: We use TY-200A standard inspection sample sheave of Scene Unification Machinery Equipment Co., Ltd. Analysis Instrument: JSM6360 Scanning Electron Microscope of Japan Electronics, D / max-2200pc XRD Radiation Diffraction Device of Japan Rigaku, LS602 Laser Particle Size Analyzer of Kuhn Hi-OMKE, FZS4-4B Type Tap Density Meter of Steel Research Institute, Pioneer2002 Surface Meter etc. , A polycrystalline Co-Ni-Mn ternary cathode material prepared by the method of the present invention is tested and analyzed.

The lithium ion secondary battery of the present invention is composed of a positive electrode, a negative electrode, a nonaqueous electrolyte, a diaphragm, and a container. The positive electrode is composed of a positive electrode active material coated on the positive electrode collector and the positive electrode collector. The positive electrode active material includes Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1 - (x + y)} Ni _x Mn _y O _{2 , Li z Ni x Mn 1 -x} O 2, Li z Co x Ni 1 - of two or more of the _{x O 2, Li 2 MnO 3} ( wherein x, y, x + y < 1, a z≥1) base Wherein the molar ratio of the metal element Li: Co: Ni: Mn is 1 to 1.2: 0.4 to 0.7: 0.2 to 0.5: 0.1 to 0.3, and the crystalline of the polycrystalline Co-Ni-Mn tri- The particle size is 8 to 20 microns, the compression density of the cathode material is 3.9 g / cm &lt; ³ &gt; Or more. The cathode is composed of a cathode collector and a cathode active material coated on the cathode collector. The diaphragm acts as a simple solid insulation layer or a conductive solid material separating the anode and the cathode. The container is a positive electrode, a negative electrode, a diaphragm, and a receptor for an electrolyte.

A lithium ion secondary battery test body is manufactured from the polycrystalline Co-Ni-Mn three-electrode cathode material produced by the present invention. Preparation of positive electrode: The polycrystalline Co-Ni-Mn three-cathode material of the present invention, the conductive carbon black which occupies 3% of the cathode material mass ratio and the PVDF adhesive of 3% Methyl pyrrolidone and uniformly stirred to prepare a slurry, which is then applied on an aluminum foil collector, dried and compressed to make extreme pieces. Negative Electrode Material: Negative Electrode Material Mesocarbon microbeads (MCMB), an active material SP, a conductive agent SP that occupies 2% of the active material mass, and PVDF, which occupies 10% of the mass ratio, are mixed and mixed at a ratio of 1: 1 N-methylpyrrolidone and uniformly stirred to form a slurry, which is then applied on a copper foil collector, dried and compressed to make extreme pieces. The diaphragm is made of PP material, and the container consists of an aluminum casing with an insulating layer and a battery lid in which a lead withdrawal hole is drilled. The positive electrode and negative electrode pieces after compression are spot-welded on the lead, the diaphragm is wound, wound on a winder, placed in an aluminum casing, the lead is drawn out from the battery lid, and the lead drawing hole is sealed with an adhesive. Aluminum casing and battery lid are welded together and sealed. The electrolytic solution is injected under an environment having a relative humidity of 1.5% or less. A mixed solvent of EC: DEC: DMC = 1: 1: 1 in mass ratio is used as the electrolyte. Lithium hexafluorophosphate of 1M is used as the electrolyte. Then seal immediately. The model of the battery is hexagon 053048.

The negative electrode active material may be a carbon-based or non-carbon-based material capable of intercalating and deintercalating lithium ions therein. For example, Li ₄ Ti ₅ O ₁₂ , amorphous tin oxide, WO ₂ , MoO ₂ , TiS _2, and a carbon-based material capable of intercalating and deintercalating lithium ions. The carbon-based material includes graphite, non-oriented graphite, coke, carbon fiber, spherical carbon, resin-type sintered carbon, vapor grown carbon and carbon nanotubes. Since the negative electrode containing the specified carbon fiber or spherical carbon exhibits a high charging efficiency, it is particularly preferable to use intermediate-phase asphalt-base carbon fibers or intermediate-phase asphalt-base spherical carbon as the carbon-based active material. Intermediate Asphaltic Carbon Fibers or Intermediate Asphaltic Spherical Carbones are obtained by well known methods. The non-aqueous electrolyte is obtained by dissolving lithium metal lithium salt LiPF ₆ containing lithium as an electrolyte in a non-aqueous agent of ethylene carbonate or dimethyl carbonate. The diaphragm may be a porous film made of polyethylene or polypropylene resin that does not dissolve in the non-aqueous agent, and a solid electrolyte of the type containing a gel electrolyte obtained from a plasticized polymer material of a non-aqueous electrolyte solution may also be used. The diaphragm may be made of a synthetic resin nonwoven fabric, a polyethylene porous membrane, or a polypropylene porous membrane.

The charge / discharge test of the lithium ion secondary battery test body manufactured according to the present invention is carried out in the test box of BS-9360 type battery of Guangzhou Qing Teng Industrial Co., Ltd. according to the test method of GB / T 18287-2000. It is explained that the larger the compression density of the pole piece is, the more active material is on the pole piece and the larger the capacity that the unit piece can exert in the positive electrode material in which the pole piece exhibits the unit volume capacity. Calculated: Extraction Compression Density (g / cm ³ ) x Initial Capacity (mAh / g).

1. Examples of precursors:

&Lt; Example 1 >

6 g of polyethylene glycol was placed in 300 ml of a LiAc solution having a concentration of 1.00 mol / L and 40 g of cobalt carbonate was added thereto. The resulting mixture was homogeneously mixed to give a cobalt content of 0.3 mol and stirred at 20 DEG C for 120 minutes at a rotation speed of 120 rpm. The mixture was dried and dehydrated at a temperature of 150 ° C for 2 hours and dispersed in a ball mill at a rotation speed of 1000 rpm for 30 minutes to obtain LiCoO ₂ Obtain a precursor.

&Lt; Example 2 >

25 g of polyethylene glycol was added to 500 ml of a LiNO ₃ solution having a concentration of 1.20 mol / L and uniformly stirred. Then, 21 g of cobalt carbonate, 21 g of nickel carbonate and 22 g of manganese carbonate previously mixed were added to obtain a cobalt content of 0.16 mol and a nickel content And the content of manganese is 0.16 mol, and the mixture is stirred for 120 minutes under the conditions of 60 DEG C and a rotation speed of 20 rpm. The mixture is dried and dehydrated at a temperature of 250 占 폚 for 10 hours and dispersed for 30 minutes in a ball mill at a rotation speed of 200 rpm to obtain a LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ precursor.

&Lt; Example 3 >

20 g of polyethylene glycol was placed in 500 ml of a LiOH solution having a concentration of 1.10 mol / L and uniformly stirred. Then, 13 g of previously mixed cobalt carbonate, 25 g of nickel carbonate and 26 g of manganese carbonate were added to obtain a cobalt content of 0.1 mol and a nickel content of 0.2 mol, and manganese content of 0.2 mol, and the mixture was stirred at 40 캜 for 120 minutes under a condition of a rotational speed of 50 rpm. The mixture is dried and dehydrated at a temperature of 200 캜 for 6 hours and dispersed for 30 minutes at a ball mill at a rotation speed of 600 rpm to obtain a LiCo _1/5 Ni _2/5 Mn _2/5 O ₂ precursor.

<Example 4>

Co (NO ₃ ) ₂揃 6H ₂ O having a Co content of 0.2 mol, Ni (NO ₃ ) ₂ .6H ₂ O having a Ni content of 0.5 mol, Mn (NO ₃ ) ₂ solution having a Mn content of 0.3 mol And dissolved in 1000 g of water to give a mass concentration of 16%. While maintaining the temperature at 30 캜 and stirring at a rotation speed of 20 rpm, a lithium nitrate aqueous solution having a lithium content of 1.2 mol and a mass concentration of 15% is gradually added dropwise and reacted for 60 minutes . 10 hours drying under 150 ℃ temperature and put in the reaction is directly the expression dewatering box and, by 30 minutes with a ball mill dispersion of the rotation speed _{1000rpm LiCo 2/10 Ni 5/} 10 Mn 3/10 O 2 Obtain a precursor.

&Lt; Example 5 >

(50%) Mn (NO ₃ ) ₂ solution containing 0.1 mol of Co (NO ₃ ) ₂ .6H ₂ O, 0.2 mol of Ni (NO ₃ ) ₂ .6H ₂ O and Mn content of 0.2 mol) Dissolved in 580 g of distilled water to make a mass concentration of 16%, while keeping the temperature at 30 캜 and stirring at a rotation speed of 20 rpm, a lithium nitrate aqueous solution having a lithium content of 1.0 mol and a mass concentration of 15% is gradually added dropwise and reacted for 60 minutes. For 6 hours and dried under 200 ℃ temperature and put in the box directly to dehydration reaction formula, and by 30 minutes with a ball mill dispersion of the rotation speed 1000rpm to obtain a _{LiCo 1/5 Ni 2/5} Mn 2/5 O 2 precursor.

&Lt; Example 6 >

(50%) Mn (NO ₃ ) ₂ solution containing 0.2 mol of Co (NO ₃ ) ₂ · 6H ₂ O, 0.2 mol of Ni (NO ₃ ) ₂ · 6H ₂ O and 0.2 mol of Mn) Dissolved in 610 g of water to give a mass concentration of 16%, and while stirring at a rotational speed of 20 rpm at a temperature of 30 캜, a lithium nitrate aqueous solution having a lithium content of 1.1 mol and a mass concentration of 15% was gradually added dropwise and reacted for 60 minutes. 3 hours drying under 250 ℃ temperature and put in the reaction is directly the expression dewatering box and, by dispersing with a ball mill for 30 minutes to obtain a rotation speed 1000rpm _{LiCo 1/3 Ni 1/3} Mn 1/3 O 2 precursor.

2. Fabrication of polycrystalline composites

The process parameters of Reference Example 7 and Example 8-9 of the precursor complex sintering method are shown in Table 1, and the battery performance test is shown in Table 4.

As shown in FIG. 1, the crystal composition of Reference Example 7 is LiCoO ₂ , LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ .

As shown in FIG. 2, the crystal composition of Example 8 is LiCoO ₂ , LiCo _2/10 Ni _5/10 Mn _3/10 O ₂ .

The composition of the crystals 3, the Example 9 is _{LiCoO 2, LiCo 2/10 Ni 5/10 Mn} 3/10 O 2, LiCo 1/3 Ni 1/3 Mn 1/3 O 2.

The process parameters of Reference Example 10 and Examples 11 to 12 of the intermediate composite sintering method are shown in Table 2, and the battery performance test is shown in Table 4.

As shown in FIG. 4, the crystal composition of Reference Example 10 is LiCoO ₂ , LiCo _1/3 Ni _1/3 Mn _1/3 O ₂ .

As shown in FIG. 5, the crystal composition of Example 11 is LiCoO ₂ , LiCo _2/10 Ni _5/10 Mn _3/10 O ₂ .

The composition of the crystals in Example 12. As shown in Figure 6: _{LiCoO 2, LiCo 1/5 Ni 2/5 Mn} 2/5 O 2, LiCo 2/10 Ni 5/10 Mn 3/10 O 2.

The process parameters of Example 13, Reference Example 14 and Example 15 of the final product composite sintering method are shown in Table 3, and the battery performance test is shown in Table 4.

The composition of the crystals in Example 13. As shown in Figure _{7: LiCoO 2, LiCo 1/5 Ni} 2/5 Mn 2/5 O 2, LiCo 2/10 Ni 5/10 Mn 3/10 O 2, LiCo 1 _/ a _{3 Ni 1/3 Mn 1/} 3 O 2.

The composition of the crystals Reference Example 14 As shown in Figure 8: _{LiCoO 2, LiCo 2/10 Ni 5/10 Mn} 3/10 O 2, LiMn 2 O 4.

As shown in FIG. 9, in Example 15 the composition of the crystals: a _{LiCoO 2, LiCo 2/10 Ni 5/10 Mn} 3/10 O 2, LiCo 1/3 Ni 1/3 Mn 1/3 O 2.

&Lt; Comparative Example 1 &

A 053048 rectangular lithium ion battery having a Co-Ni-Mn molar ratio of 0.2: 0.5: 0.3 was prepared from Co-Ni-Mn trivalent ZH5000R of Sun Display Jinhwa New Material Co., Ltd. as a battery active material. The performance of the battery is shown in Table 5. The discharge capacity of the unit capacity is 560.4 mAh / cm ^{3 at a} discharge magnification of 0.5 to 1.0 C, and the cyclic capacity retention ratio at 150 cycles is 94% and the cyclic capacity retention ratio at 300 cycles is 85%.

&Lt; Comparative Example 2 &

053048 quadrangular lithium ion battery is manufactured using lithium cobalt oxide ZHT08 of Sun Display Jinhwa New Material Co., Ltd. as a battery active material. The performance of the battery is shown in Table 5. Geukpyeon capacity exhibited in the unit volume is 577.9mAh / cm ^3, and in the discharge ratio 0.5 ~ 1.0C, and capacity retention rate of 150 cycles was 90%, and 300 cycle capacity retention rate was 84%.

&Lt; Comparative Example 3 &

Co-Ni-Mn ternary ZH3000 of commercially available Sun Display Jinhua New Materials Co., Ltd. was used as a battery active material and a 053048 rectangular lithium ion battery having a Co-Ni-Mn molar ratio of 1/3: 1/3: . The performance of the battery is shown in Table 5. The discharge capacity of the unit volume is 480.7 mAh / cm ^{3 at a} discharge capacity of 0.5 to 1.0 C, the circulation capacity retention ratio at 150 cycles is 95%, and the circulation capacity retention ratio at 300 cycles is 89%.

The experimental results show that the unit volume capacity of the polycrystalline composite of the present invention is superior to lithium cobalt oxide and Co-Ni-Mn ternary single crystal materials. 3.9g / cm ³ It is advantageous to increase the energy density if the material is composed of a material having a relatively high nickel content in the crystal structure.

Claims (7)

Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , and Li ₂ MnO ₃ (wherein x, y, x + y &lt; 1, z? 1), and has a polycrystalline layer structure and has a molar ratio of element Li: Co: Ni: Mn = 1 to 1.2: 0.4 to 0.7: 0.2 to 0.5: 0.1 to 0.3, a particle size of 8 to 20 microns, a compression density of 3.9 to 4.3 g / cm ³ , a discharge capacity of 0.5 to 1 C, and a capacity of 145 mAh / g Or more and a cyclic capacity retention rate of 300 times or more is 90% or more. A method for producing a polycrystalline Co-Ni-Mn three-electrode material comprising the steps of:
1. Preparation of Precursor: 6 to 25 g of polyethylene glycol was placed in 300 to 500 ml of LiAc, LiOH or LiNO ₃ solution having a lithium element concentration of 1.0 to 1.2 mol / L, and at least one kind of salt compound of Co, Ni and Mn elements And the mixture was stirred for 120 minutes under the conditions of 20 to 60 캜 and a rotation speed of 20 to 120 rpm so that the total content of the elements of Co, Ni and Mn was 0.3 to 1.0 mol, Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , and Li _z Co _{1- (x + y)} were obtained by drying and dewatering at a temperature of 150 to 250 ° C. for 2 to 10 hours and dispersing in a ball mill at a rotation speed of 200 to 1000 rpm for 30 minutes _. Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ or Li ₂ MnO ₃ wherein x, y, x + y < ) Oxide precursor;
2. Preparation of Polycrystalline Co-Ni-Mn Ternary Cathode Materials The precursory composite sintering method is used for the preparation of the polycrystalline Co-Ni-Mn ternary anode materials: Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O _{2 , Li z Ni x Mn 1-} x O 2, Li z Co x Ni 1-x O 2, Li 2 MnO 3 for the oxide precursor two or more of Li: Co: Ni: Mn molar ratio is 1 to 1.2: 0.4 and 0.7 to 0.2: 0.5: 0.1 to 0.3, the mixture is directly put into a box type furnace and sintered at a temperature of 750 to 950 ° C for 5 to 15 hours, Air cooling to lower the temperature to room temperature to carry out the air flow pulverization and obtain a polycrystalline Co-Ni-Mn three-way cathode material at an air pressure of 0.4 to 1.0 MPa;
Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ precursors were directly put into a box type furnace and sintered at a temperature of 600 to 850 ° C for 5 to 15 hours. The molar ratio of Li: Co: Ni: Mn = 1 ~ 1.2: 0.4 to 0.7: 0.2 - 0.5: according to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- (x + y) Ni x Mn y O 2, Li z The initial sintered product of two or more precursors in Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ was homogeneously mixed with a ball mill at a rotation speed of 500 rpm for 60 minutes, And sintered under the temperature of 750 ~ 980 ℃ for 4 ~ 10 hours. The mixture was cooled to room temperature and the air flow was pulverized. The pressure of 0.4 ~ 1.0MPa was applied to the polycrystalline Co-Ni-Mn tri- Get;
Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Each of the precursors of Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ was put directly into a box-type furnace, sintered at a temperature of 850 to 980 ° C for 5 to 10 hours, air-flow pulverized, , And classified by a sample sheave to have a particle size D50 of 8 to 20 microns. Li: Co: Ni: Mn molar ratio is 1 to 1.2: 0.4 to 0.7: 0.2 - 0.5: According to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- (x + y ₎ Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , and Li ₂ MnO ₃ are homogeneously mixed and put into a direct box type furnace , Sintered at 350 to 850 ° C for 0.5 to 5 hours, air-jet pulverized, and 0.4 to 1.0 MPa in air pressure to obtain a polycrystalline Co-Ni-Mn three-way cathode material. 3. The method of claim 2, wherein the Co, Ni, Mn salt compound is a hydroxyl compound, an oxalate salt, or a carbonate salt. 4. The method for producing a polycrystalline Co-Ni-Mn three-electrode material according to claim 3, wherein the air flow is classified into a sample sheave after milling to control the particle size to D50 = 8 to 20 microns. A method for producing a polycrystalline Co-Ni-Mn three-electrode material comprising the steps of:
1. Preparation of Precursor: An aqueous nitrate solution having a mass concentration of 16% was prepared from nitrate having a total content of at least one of Co, Ni, and Mn of 0.5 to 1.0 mol, and the mixture was heated at 30 to 80 캜 and at a rotation speed of 20 to 120 rpm Lithium nitrate aqueous solution having a lithium element content of 1.0 to 1.2 mol and a mass concentration of 10 to 25% is gradually added dropwise and reacted for 60 to 120 minutes. Then, the reacted material is directly introduced into a box type furnace and heated at a temperature of 150 to 250 ° C. for 2 to 10 Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , and Li _z Ni ₂ O ₃ by dispersing them for 30 minutes at a rotating speed of 200 to 1000 rpm. to obtain an oxide precursor of _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ or Li ₂ MnO ₃ (wherein x, y, x + y <1, z? 1);
2. Preparation of Polycrystalline Co-Ni-Mn Ternary Cathode Materials The precursory composite sintering method is used for the preparation of the polycrystalline Co-Ni-Mn ternary anode materials: Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O _{2 , Li z Ni x Mn 1-} x O 2, Li z Co x Ni 1-x O 2, Li 2 MnO 3 for the oxide precursor two or more of Li: Co: Ni: Mn molar ratio is 1 to 1.2: 0.4 and 0.7 to 0.2: 0.5: 0.1 to 0.3, the mixture is directly mixed in a ball mill at a rotating speed of 200 to 1000 rpm for 60 minutes, and then the mixture is directly put into a box type furnace and sintered at a temperature of 750 to 950 ° C for 5 to 15 hours. Cooled to a room temperature, subjected to air flow pulverization, and subjected to a pressure of 0.4 to 1.0 MPa to obtain a polycrystalline Co-Ni-Mn triode cathode material;
Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ were directly put into a box furnace and sintered at a temperature of 600 to 850 ° C for 5 to 15 hours for initial sintering. The molar ratio of Li: Co: Ni: Mn = 1 ~ 1.2: 0.4 to 0.7: 0.2 - 0.5: according to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- (x + y) Ni x Mn y O 2, Li z The initial sintered product of two or more precursors in Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ was homogeneously mixed with a ball mill at a rotation speed of 500 rpm for 60 minutes, And sintered under the temperature of 750 ~ 980 ℃ for 4 ~ 10 hours. The mixture was cooled to room temperature and the air flow was pulverized. The pressure of 0.4 ~ 1.0MPa was applied to the polycrystalline Co-Ni-Mn tri- Get;
Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Each of the precursors of Li _z Co _x Ni _1-x O ₂ and Li ₂ MnO ₃ was put directly into a box-type furnace, sintered at a temperature of 850 to 980 ° C for 5 to 10 hours, air-flow pulverized, , And classified by a sample sheave to have a particle size D50 of 8 to 20 microns. After that Li: Co: Ni: Mn molar ratio of 1 ~ 1.2: 0.4 to 0.7: 0.2 - 0.5: According to _{0.1 ~ 0.3, Li z CoO 2} , Li z NiO 2, Li z MnO 2, Li z Co 1- _{(x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni _1-x O ₂ , and Li ₂ MnO ₃ are uniformly mixed, And sintered at a temperature of 350 to 850 ° C for 0.5 to 5 hours and air-jet milled to obtain a polycrystalline Co-Ni-Mn three-way cathode material at an air pressure of 0.4 to 1.0 MPa. The method for producing a polycrystalline Co-Ni-Mn three-electrode material according to claim 5, wherein the air flow is classified into a sample sheave after milling to control the particle size to D50 = 8 to 20 microns. 1. A lithium ion secondary battery comprising a positive electrode material,
Wherein the cathode material is selected from the group consisting of Li _z CoO ₂ , Li _z NiO ₂ , Li _z MnO ₂ , Li _z Co _{1- (x + y)} Ni _x Mn _y O ₂ , Li _z Ni _x Mn _1-x O ₂ , Li _z Co _x Ni (Li: Co: Ni: Mn) having two or more kinds of base crystal structure among _1-x O ₂ and Li ₂ MnO ₃ (x, y, x + y & Mn is in the range of 1 to 1.2: 0.4 to 0.7: 0.2 to 0.5: 0.1 to 0.3, the particle size is 8 to 20 microns, the compression density is 3.9 to 4.3 g / cm ³ and the discharge magnification is 0.5 to 1C. Is 145 mAh / g or more, and the cycling capacity retention ratio of 300 times is 90% or more.

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